1. Field
One or more exemplary embodiments relate to a lens system, and more particularly, to a variable liquid lens system having a focal length adjusting function or a zooming function.
2. Description of the Related Art
In the field of medical imaging, there is increasing demand for information on the surface of tissue (human body tissue or skin tissue) and a technique for precisely capturing sectional images underneath these surfaces. In particular, most cancers occur under epithelial cells and then spread into dermal cells where blood vessels are present, and thus early detection of cancer may remarkably reduce damage due to the cancer. Internal tomograms may be obtained through the skin by using an existing imaging technique, such as magnetic resonance imaging (MRI), x-ray computed tomography (CT), ultrasonic imaging, or similar. However, due to the low resolution of the tomograms, early detection of cancer, which is small in size, is difficult. On the other hand, a recently introduced optical coherence tomography (OCT) technique uses light, unlike existing techniques of the related art. Thus, the OCT technique is expected to be useful in detecting early cancer with a size of about 50 μm to about 100 μm because the OCT technique has a resolution approximately ten times greater than that of the ultrasonic imaging technique even though its penetration into the skin is as low as about 2 mm to about 3 mm.
In the OCT technique, as well as in various fields where optical devices are used, there is demand for adjusting a position on which light is focused or the size of an irradiated light spot, and for miniaturizing such optical devices.
To accommodate such demand for the focal length adjusting function or the zooming function and miniaturization, a liquid lens is provided. A liquid lens does not involve any mechanical movement, and the focus and magnification thereof may be adjusted.
A liquid lens involves a liquid dispensing process. Due to recent advances in microfluidic technology, a technique for dispensing liquid at a picoliter (pL) level is under development together with various liquid-based devices.